1. Field of the Invention
This invention relates generally to apparatus for monitoring the validity of multiplexed digital input signals. More particularly, this invention relates to apparatus of the type described which has self testing characteristics.
2. Description of the Prior Art
Control systems such as may be used for controlling aircraft engines may include manually operated controllers which provide digital signals corresponding to parameters being controlled. Monitoring systems of this type require that the digital signals be multiplexed to reduce the redundancy of circuit components. Further, it is important that the validity of the signals be monitored and an indication be provided when the signals are invalid. Finally, the monitoring apparatus must be self testing to minimize system integrity.